In general, a small-sized camera module is mounted in mobile terminals such as smartphones. A lens driving device having an autofocus function of automatically performing focusing during capturing of a subject (hereinafter referred to as “AF (Auto Focus) function”) and a shake-correcting function (hereinafter referred to as “OIS (Optical Image Stabilization) function”) for reducing irregularities of an image by correcting shake (vibration) caused during capturing of an image is applied in such a camera module (see e.g. Patent Literature (hereinafter referred to as “PTL”) 1).
The lens driving device having the autofocus and shake-correcting functions is provided with an auto-focusing driving part for moving a lens part in the optical-axis direction (hereinafter referred to as “AF driving part”) and a shake-correcting driving part for swaying a lens part in a plane orthogonal to the optical-axis direction (hereinafter referred to as “OIS driving part”).
The AF driving part includes, for example, an auto-focusing coil (hereinafter referred to as “AF coil”) disposed at the periphery of the lens part, an auto-focusing magnet (hereinafter referred to as “AF magnet”) disposed to be radially spaced apart from the AF coil, and an elastic supporting part (for example, plate spring) for elastically supporting an autofocus movable part (hereinafter referred to as “AF movable part”) including the lens part and the AF coil, for example, with respect to an autofocus fixing part (hereinafter referred to as “AF fixing part”) including the AF magnet. Focusing is automatically carried out by moving the AF movable part with respect to the AF fixing part in the optical-axis direction by utilizing a driving force of a voice coil motor composed of the AF coil and the AF magnet. In the meanwhile, the AF fixing part may include the AF coil and the AF movable part may include the AF magnet.
The OIS driving part includes a shake-correcting magnet (hereinafter referred to as “OIS magnet”) disposed, for example, to the AF driving part, a shake-correcting coil (hereinafter referred to as “OIS coil”) disposed to be spaced apart from the OIS magnet, and a supporting part configured to support a shake-correcting movable part (hereinafter referred to as “OIS movable part”) including the AF driving part and the OIS magnet with respect to a shake-correcting fixing part (hereinafter referred to as “OIS fixing part”) including the OIS coil. A shake correction is performed by swaying the OIS movable part with respect to the OIS fixing part in a plane orthogonal to the optical-axis direction by utilizing a driving force of a voice coil motor composed of the OIS magnet and the OIS coil (so-called barrel shift system). The OIS magnet can also serve as the AF magnet, and in this case, the miniaturization and/or the height reduction of the lens driving device can be achieved. In addition, a suspension wire is employed as the supporting part configured to support the OIS movable part with respect to the OIS fixing part, for example.